This disclosure relates to develop high performance sealable oriented film, methods of manufacture thereof and to articles comprising the same.
Co-extruded oriented film products that comprise polypropylene (PP) and polyethylene (PE) are often used for packaging food products. Presently, dry food packaging is dominated by multi-ply dry laminated biaxially oriented polypropylene (BOPP) film, which is usually made by adhesive-laminating a BOPP film with a sealant film like PE and cast PP (CPP) film.
It is desirable to eliminate the lamination process, and replace the laminate with a single ply film while still maintaining the laminate film performance, like seal strength, stiffness and dimensional stability. The co-extruded BOPP films afford poor heat seal performance after biaxial stretching. Due to the lack of the seal strength, the co-extruded BOPP films can only be used to package small articles, articles not requiring high seal strength, and small size and light weight food. There is therefore a need in the food packaging industry to develop a high heat seal strength oriented film to replace the incumbent laminated structure (such as BOPP//CPP and BOPP//PE) to cut cost and eliminate the adhesive involved in the lamination process.